The present invention relates to a drug delivery system. In particular the present invention relates to a pocket size or hand held ultrasonic-pulmonary drug delivery system.
In many medical applications it is necessary to make aerosols from liquids and powders. One of the therapeutic medical uses of ultrasound waves is in liquid aerosol mist production. Aerosol mist production makes use of a nebulizer or inhaler to produce an aerosol mist for creating a humid environment and delivering a drug to the lung.
Particularly for oral-pulmonary applications it is necessary to atomize medications, such as antibiotics, insulin, asthma drugs, and other drugs to make an aerosol that reaches the mouth, boucle, intestine and consequently the lungs.
Ultrasonic nebulizers operate by passing ultrasound waves of sufficient intensity through a liquid, the waves being directed at an air-liquid interface of the liquid from a point underneath or within the liquid. Liquid particles are ejected from the surface of the liquid into the surrounding air following the disintegration of capillary waves produced by the ultrasound. This technique can produce a very fine dense fog or mist. Aerosol mists produced by ultrasound are preferred because a smaller particle size of the aerosol can be obtained with the ultrasonic waves.
One of the major shortcomings of known ultrasonic inhalers and nebulizers is that there is no directed aerosol to the target. Therefore, an air stream is required to direct the aerosol to the target; however, this decreases the efficiency of ultrasound mist.
The device of the present invention comprises a means for creating a directed spray of liquid or powder particles produced by contact of the liquid or powder with a radiation surface of any ultrasound transducer such as, for example, a piezofilm or ultrasound tip. The ultrasonic waves cause the spray to project outwardly from the radiation surface of the transducer, and a particle spray is directed to the mouth.
Accordingly, the device of the present invention generates a directed particle spray, created by ultrasound waves, into a mouth and delivers a sharp dosage of a uniform up to 90% particle size drug.
Furthermore, the ultrasound waves used in the device energize the drug and cause penetration of the drug below the surface of the tissue.
Finally, the device of the present invention for drug delivery is particularly advantageous when sharp dosage drug delivery is desirable, such as, for example, with insulin for diabetic care. Piezoelectric oscillatory and liquid atomization system, is known with a bending oscillator or working plate for atomization of liquid. A disadvantage of these piezoelectric atomizers is that the particle sizes are not uniform and particle sizes of about 0.1 micron to several millimeters are obtained. The particles of larger diameter must be retained by means of a mechanical droplet separator.
A number of prior art references are available in the art, each of which references are directed to some specific discreet elements of the system which is described and claimed in the present invention, however, none of which is directed to the totality of the combination, or its use and function in the manner described and claimed herein:
Ultrasonic sprayers from Sonic and Materials, Inc., Misonix, Inc., Sono-Tek, Inc., Zevex International, Inc. U.S. Pat. Nos. 3,765,606, 4,659,014, 5,104,042, 4,930,700, 4,153,201, 4,655,393, 5,516,043, 5,835,678, 5,879,364 and 5,843,139, etc., operate by passing liquid through a central orifice of an ultrasound instrument tip which creates problems with dosage control, heating of the drug, non-uniform particles, and other related difficulties.
Ultrasonic inhalers and drug delivery systems from Medisonic USA, Inc., 3M, Siemens Gmb, The Procter Gamble Company, Sheffield Pharmaceuticals, Aradigm, Inc., U.S. Pat. Nos. 4,294,407, 5,347,998, 5,520,166, 5,960,792, 6,095,141, 6,102,298, 6,098,620, 6,026,808, and 6,106,547, operate by atomizing liquid using piezoceramic film and air/propellant.
U.S. Pat. No. 4,912,357 describes a MHz oscillator with a concave surface adapted to the defined (limited Vxe2x89xa6) liquid quantity to be atomized.
In U.S. Pat. No. 5,950,619 a propellant is used along with ultrasound. Another disadvantage of this device is that the atomization surface is button shaped, which creates uniform particles, and the distance between valve and atomization surface is hardly achievable in industrial assemble process (0.1 to 0.5 mm).
U.S. Pat. Nos. 5,586,550, 5,758,637, 5,938,117, 6,014,970, and 6,085,740 are based in driving liquid through the hole made on a piezofilm""s working area. Bending waves are used, which spray non-uniform liquid particles.
U.S. Pat. No. 5,261,601 describes an atomizer having a membrane covering a liquid chamber. U.S. Pat. No. 4,533,082 describes a liquid sprayer with multiple orifices on the vibrating element.
It is an object of the present invention to provide an improved device for oral pulmonary drug delivery.
It is also an object of the present invention to provide an improved device for oral pulmonary drug delivery using ultrasonic waves.
It is another object of the present invention to provide a device for the delivery of drugs ultrasonically with high efficiency.
It is yet another object of the present invention to provide a device for the delivery of drugs without the use of air or other propellants.
It is therefore an object of the present invention to provide a device for delivering drugs which affords highly precise dosage control.
It is a further object of the present invention to provide a method for the delivery of uniformed particles of a drug using ultrasonic waves.
These and other objects of the invention will become apparent from the following discussion below.
The present invention provides for a drug delivery system. More particularly the present invention provides for a pocket size or hand held ultrasonic oralxe2x80x94pulmonary liquid and powder drug delivery device.
In one embodiment the device of present invention is characterized in that it is able to produce a spray and deliver it to the oral/pulmonary tract, without use of air or other propellants and with such spray having greater than about 90% uniform particle size, with a high degree of dosage control.
The device of the invention comprises means for creating a directed spray of liquid or powder particles produced by contact of the liquid or powder with a radiation surface of ultrasound transducer such as, for example, a piezofilm/disk or ultrasound tip. The ultrasonic waves produced cause the spray to project outwardly from the radiation surface of the transducer. The particle spray is directed into the mouth for oral/pulmonary delivery.
According to the device of the present invention directed particle spray, created by ultrasound waves into a mouth delivers sharp dosage and uniform up to 90% particle size drug.
Furthermore, the ultrasonic waves used in the device, energize the drug and cause penetration of the drug below the surface of the tissue.
Finally, the device of the invention for drug delivery is particularly advantageous when sharp dosage drug delivery is desirable, such as in insulin therapy for diabetic care, and similar applications.
The construction and obvious advantages of the system provided for by the present invention will be more clearly understood from the following description of the various specific embodiments when read in conjunction with the accompanying drawings.